1) Embedding a Kaltura video in a Canvas course using the rich text editor adds a "Category" to the metadata of that video. This is how Kaltura gives course participants permission to view the video.

2) Each Kaltura video can be associated with at most 32 categories. This is a hard limit in Kaltura. 

3) The owner of a video always has permission to view it, so they might not realize that there's an error when embedding a video in a course.

Affects:

Specific Kaltura videos which have already been embedded in enough Canvas courses to reach 32 categories. 

Students and visitors in courses after the 32nd will see an "Access Denied" message instead of the video. To the instructor who embedded the video, the video will display normally.

As of 09/05/2019, the issue is still present. There are multiple workarounds.

Instructors can use the Student View feature to check if their Kaltura videos display correctly in Canvas courses.

Instructors who plan on using a Kaltura video in dozens of courses can follow the instructions in the "Insert with HTML Embed Code" section of the Kaltura - Inserting Videos in Canvas guide. Using embed code rather than the rich-text-editor bypasses this issue.

Instructors who plan on using a Kaltura video in dozens of courses can also use Kaltura's editing feature (Canvas > Account > My Media > [Media] > Edit > Launch Editor) to create multiple copies of a video. Each copy can have up to 32 categories.